Hi,

I was working on this problem: https://mirror.codeforces.com/contest/771/problem/A

By adding a return in front of my recursive call in the function "dfs2," I was able to get AC on this problem. Can anyone please explain why?

Difference:

bool dfs2(int u)
{
	if(vis[u])
		return false;
	vis[u] = 1;
	if(adj[u].size() != cur_sz - 1)
		return false;
	for(int v : adj[u])
		if(!vis[v])
			dfs2(v);
	return true;
}

as opposed to

bool dfs2(int u)
{
	if(vis[u])
		return false;
	vis[u] = 1;
	if(adj[u].size() != cur_sz - 1)
		return false;
	for(int v : adj[u])
		if(!vis[v])
			return dfs2(v);
	return true;
}

WA submission: https://mirror.codeforces.com/contest/771/submission/69394496 AC submission: https://mirror.codeforces.com/contest/771/submission/69395025